(1) Field of the Invention
The present invention relates to a stator used in a rotating electric machine, and in particular to a structure for supporting a stator core to a stator frame.
(2) Description of Related Art
As to a structure (which will be hereinafter occasionally referred to as a stator core support structure) for supporting a stator core to a stator frame in the rotating electric machine as stated above, for example, JP-A-58-006658 discloses the provision of a columnar pressure transmission rod for absorbing vibrations.
Further, JP-A-58-222747 discloses a structure capable of using a loose-jointed bolt for fixing a spring bar in the stator frame with a reamer bolt in view of such a fact that the spring bar can be fixed in the stator frame without the necessity of a high degree of positioning accuracy.
Further, JP-A-63-253840 discloses a structure such that a ring plate welded to the inside of a stator frame is fixed at its inner periphery to a key bar fitted in a key slot axially formed in the outside of the stator core by means of adjustable bolts so as to apply a radial tension to the stator core.
However, a conventional stator core support structure is such that the stator core is elastically supported by a columnar pressure transmission rod in its axial direction, that is, a pressure transmission rod having a circular cross-sectional shape is used.
Thus, a ratio between the radial and circumferential stiffness of elastic support bars (which will be occasionally referred to simply as “rod”) which are arranged around the stator core cannot be changed. Thus, it has been difficult to set the circumferential and radial stiffness of the elastic support bars for supporting the stator core to values which are appropriate in view of a relationship between torque transmission and vibration prevention for the stator frame.
Further, the structure in which the spring bar is fixed to the stator frame by the reamer bolts and the structure in which the ring plate welded to the stator frame is coupled to the key bar fitted in the stator core by the adjustable bolts have caused problems in view of the assembly by fastening the bolts.